Introduction
For individuals with glaucoma, canaloplasty is a relatively recent non-penetrating procedure that lowers intraocular pressure. A tension suture that creates an inward distension is left in place after performing a 360-degree cannulation of Schlemm's canal using a microcatheter. It is unrelated to the healing of exterior wounds and tries to restore the normal outflow routes of the aqueous humor.
Compared to trabeculectomy, the gold standard for glaucoma surgery, several studies have demonstrated that canaloplasty efficiently lowers intraocular pressure and has a low risk of complications. The combination of cataract phacoemulsification and canaloplasty may further reduce intraocular pressure in individuals with mild to moderate open-angle glaucoma.
What Is Glaucoma?
Glaucoma can affect both eyes and lead to damage to the optic nerve. When fluid accumulates in the area of the eye closest to the nose, it often happens. The eye's pressure rises due to that excess fluid, harming the optic nerve. The eye produces humor in water continually. The same volume of aqueous fluid should drain out as it enters the eye.
The drainage angle, where the fluid exits, is where this happens. Intraocular pressure, often known as IOP, is maintained steadily via this procedure. But if the drainage angle is not functioning properly, fluid accumulates. The optic nerve is harmed by increased intraocular pressure.
The most prevalent kind of glaucoma is open-angle glaucoma. The eye progressively stops draining fluid as effectively as it should, much like a plugged drain. As a result, the optic nerve begins to suffer damage as eye pressure increases. This kind of glaucoma initially has no symptoms or impact on vision.
There are no early symptoms or warning indications of open-angle glaucoma. Blind spots appear in the peripheral (side) vision as the condition worsens. Most people with open-angle glaucoma only detect changes in their vision once the damage is fairly severe. Glaucoma is known as the "silent thief of sight."
What Is Canaloplasty?
The only treatment for glaucoma that has been proven effective is lowering intraocular pressure (IOP). Traditional glaucoma filtration procedures, such as trabeculectomy, effectively reduce intraocular pressure but have a very high risk of complications. This prompted researchers to look for safer glaucoma surgical procedures.
A surgical procedure called canaloplasty encourages the natural aqueous outflow via the trabecular meshwork (TM) and into Schlemm's canal (SC). Multiple regulated direct injections of an ocular viscoelastic device (OVD) are delivered by a flexible microcatheter threaded through the full length of Schlemm's canal to dilate Schlemm's canal. An intraluminal suture is inserted into Schlemm's canal and securely knotted to create a long-lasting tensioning action to sustain this dilatation.
This works to maintain the Schlemm's canal open and stop it from collapsing, as well as to stretch the trabecular meshwork and make it more permeable to water. This surgery should be less likely to result in hypotony and its associated consequences because aqueous filtration is guided towards Schlemm's canal and the already-existing natural outflow channels. This should make it far safer than conventional glaucoma filtration procedures.
Comparing canaloplasty to trabeculectomy, there are various benefits. As long as goniopuncture is avoided, bleb-related problems are often avoided since there is rarely a bleb. Since the aqueous fluid can drain via the normal outflow system, intraocular pressure should not be able to go below episcleral venous pressure and hypotony, and all of its problems may generally be avoided. Visual recovery is usually completed more quickly, and postoperative care and follow-up are easier and less demanding.
What Are the Advantages of Canaloplasty?
Canaloplasty has a number of benefits.
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It is a non-penetrating, minimally invasive method that does not need a bleb or result in a long-term fistula in the eye's wall.
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It avoids the range of bleb-related risks that can accompany conventional glaucoma surgery.
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In addition to eliminating bleb-related complications, such a minimally invasive surgical approach significantly lowers IOP over the long term and lessens the need for glaucoma medications.
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It is a good option for open-angle glaucoma patients not yet prepared for more invasive traditional surgeries like trabeculectomy or tube shunts.
What Are the Indications and Contraindications of Glaucoma?
Indications - Open-angle glaucoma patients typically undergo canaloplasty. It is especially beneficial for young patients with clear lenses since it lessens the risk of cataract advancement. Additionally, it should be considered for high myopes who would be at high risk for hypotony following a trabeculectomy procedure. It would also be fantastic for individuals with aphakia, where the vitreous may block the sclerotomy or tube during conventional glaucoma filtration procedures.
Contraindications - Congenital glaucoma, small angles, recession of the angle, and circumstances involving high episcleral venous pressure are a few examples of relative contraindications. Glaucoma with angle closure would be a strict contraindication.
How to Diagnose Glaucoma?
A thorough eye exam is the only reliable approach to identifying glaucoma. It is insufficient to detect glaucoma using a glaucoma screening that merely measures ocular pressure.
In a glaucoma examination, the ophthalmologist will:
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To check the eye pressure.
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Review the drainage angle in the eye.
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Examine the health of the optic nerve.
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Measure the clarity of the side vision.
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Take a photo of or measure the optic nerve using a computer.
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Determine the cornea's thickness.
Conclusion
The most popular surgical method for decreasing pressure is called trabeculectomy, which involves making a hole in the sclera so that the aqueous fluid may drain into the outer cyst or bleb. Although trabeculectomy is currently the surgical gold standard, there are risks like infection, leaking, and discomfort.
In order to increase the drainage channel and relieve pressure inside the eye, a microcatheter or tube is inserted into the Schlemm channel (the natural drainage location for healthy eyes). Patients with open-angle glaucoma who have had difficulties after trabeculectomy in the other eye or are at high risk for infection or hemorrhage might consider canaloplasty a beneficial surgical alternative.
Contact lens wearers can be suitable candidates for this surgery. In conclusion, canaloplasty is a safe and cutting-edge technique using the eye's natural drainage mechanism to relieve increased pressure in glaucoma patients properly.
